Skyscrapers and Environment
In the late 1960's，many people in North America turned their attention to environmental problems，and new steel-and-glass skyscrapers were widely criticized. Ecologists pointed out that a cluster of tall buildings in a city often overburdens public transportation and parking lot capacities.
Skyscrapers are also lavish consumers，and wasters，of electric power. In one recent year，the addition of 17 million square feet of skyscraper office space in New York City raised the peak daily demand for electricity by 120，000 kilowatts-enough to supply the entire city of Albany，New York，for a day.
Class-walled skyscrapers can be especially wasteful. The heat loss（or gain）through a wall of half-inch plate glass is more than ten times that through a typical masonry wall（砌筑墙）filled with insulation board（隔热板）.To lessen the strain on heating and air-conditioning equipment，builders of skyscrapers have begun to use double-glazed panels of glass，and reflective glasses coated with silver or gold mirror films that reduce glare as well as heat gain. However，mirror-walled skyscrapers raise the temperature of the surrounding air and affect neighboring buildings.
Skyscrapers put a severe strain on a city's sanitation facilities，too.If fully occeupied，the two World Trade Center towers in New York City would alone generate 2.25 million gallons of raw sewage each year-as much as a city the size of Stanford，Connecticut，which has a population of more than 109，000.
【第13题】According to the passage,which aspect of skyscrapers were some residents of North America concerned with in the late 1960's?
A、 The poor reception of radio and TV signals.
B、 The removal of trees and grass from building sites.
C、 The harmful effects on the city's plans.
D、 The obstruction of air traffic.
【正确答案】：C
【题目解析】：第一段第二句话：生态学家指出，城市中密集的高层建筑经常给公共交通与停车场的承载能力造成过重的负担。这些正是对城市规划的负面影响，因此选择C。
